Hand-operated abrader



Dec. 28, 1948.

A. N. HANNA HAND OPERATED ABRADER Filed Nov. 28, 1945 IN VEN TOR.

A TTO N. HAN/VA Patented Dec. 28, 1948 UNITED STATES PATENT OFFICE HAND-PERATED ABRADER Atto N. Hanna, Atlantic Highlands, N. J. Application November 28, 1945, Serial No. 631,297

1 Claim. 1

applied. The use of wooden blocks to act as supports for the sandpaper or emery cloth is an old expedient, but there are many disadvantages attendant upon such use. In particular might be mentioned the difficulty of obtaining a block suitably shaped for various sandpapering demands, the tendency of the sandpaper to slip from said block, particularly when pressure is applied, and the less efficient use of sandpaper when applied by such a block in that all of the abrasive surface cannot effectively be applied against the surface of the article tobe smoothed.

It is a prime object of the present invention to provide a simple but effective supporting block for sandpaper and similar flexibly backed abrasive elements.

It is a further object of this invention to pro.-

vide such a black wherein sandpaper consumption can be materially reduced by providing for effective use of the entire abrasive surface.

It is a further object of this invention to provide such a block wherein the sandpaper will not slide on the block, thus making the sanding operation much less difficult.

It is a further object of this invention to provide such a block wherein various sized supporting surfaces are provided to meet the various sizes and types of surface to which the sandpaper might be applied.

It is a further object of this invention to pro vide such a block wherein replacement of the worn-out sandpaper may be quickly and easily accomplished, even by the unskilled operator.

To the accomplishment of the foregoing-ob jects and such other objects as may hereinafter appear, the present invention resides in thecombination of a supporting block, a flexible abrasive strip, and expansible means as herein described and as defined in the appended claim. 4

In the appended drawing:

Fig. l is a perspective view of a preferred embodiment of the present invention;

Fig. 2 is a side view of a supporting block of this embodiment with the flexible abrading ele ment and the expansible member removed;

Fig. 3 is an end view of the supporting block shown in Fig. 2;

Fig. 4 is a perspective View of one type of expansible member that may be used; and

Fig. 5 is a perspective view of the continuous strip of an abrading element employed with the supporting block.

The invention consists of a supporting block,

nerally designated as A, which is so constructed as to be conveniently grasped by the operator's hand and at the same time to present to the surface to be abraded a suitably shaped support surface. backed abrasive strip in continuous form, generally designated as B, which abrasive strip is supported by the block A with its abrasive surface outermost and is, during the abrading oper. ation, held firmly between the support surface of the block A and the surface to be abraded The abrasive strip B is releasably held under tension on the support block by a contractible.

and expansible means, generally desiganted as C.

In the embodiment of the invention disclosed generally in Fig. l, and more in detail in Figs. 2 to 5, the supporting block A is provided with long, flat top and bottom walls 2 and d, and short,

rounded end walls 5 and 8, which walls comprise] the supporting surfaces for the flexibly backed the abrasive strip B to be readily removed and replaced, and in order to hold that strip-under tension during the abrading operation. As illustrated in Fig. 4, it consists of a pusher-bar [4 with its outer surfacewhich is also the end wall 8-narrow1y convex in shape. mounted on two supporting arms iii, which arms are adapted to loosely fit into holes is drilled into one end of the block proper. ably surrounding each arm i6 is a coil spring 20.

' Whenthe block proper, the pusher-bar I 4, .sup,

porting arms Hi, and the springs 20 are assem-, bled, the upper end 22 of each springabuts.

against the pusher-bar I l and the lower end 24 is compressed against a shoulder 25 in the block 10 formed by counter-sunk holes 28, concentric This block is enveloped by a flexibly.

the

This bar is:

Loosely and slidwith the holes N3, of greater diameter than the port which is very advantageous in sanding very said holes, but of such a lesser depth as to permit narrow surfaces such as edges or for getting into unrestricted motion of the arms 16 in the holes tight corners.

l8 throughout the full range of compressibility While I have disclosed the preferred form of of the springs 20. External pressure on the construction of this hand-operated abrader, it pusher-bar M in the direction shown by the will be obvious that many changes may bemade arrow of Fig. 1 will compress the springs 29, thus in the structure without departing from the indecreasing the effective longitudinal dimension vention defined in the following claim.

L of the..block Hi. When external pressure is, Lelaim: released,. the compressedsprings 20"wil1 force::thei 10 A; handoperated abrade-ra comprising a suppusher-bar 54 away from the block proper H), porting block" having endwall's, opposite side walls thus increasing its longitudinal dimension L. and long fiat top and bottom walls, said top and The flexibility backed abrasive strip B, adapted bottom walls being parallel, said opposite side to be fitted over the block assembly as'r aboveede-i wallsihavinglhand hold depressions, one of said scribed, is'shown in Fig. 5. It consists..of a.strip .15 end wallsbeing smoothly and bluntly curved and 30, as of sandpaper, or emery cloth; or 'oth'erfiexthe 'otli'er'of'saidend Walls having a central fiatibly backed abrasive material; cutL-to;a'ppropi:iaztelv tenedzportiom.saideblock having a pair of holes length and breadth from any suitable commereextending inwardly parallel to said top and botcial product, and having,.its two ends 32 and'3'4' tom" walls from said flattened portion of said fastened together in any convenient manner, as other of said end walls, said holes being provided for example; bymeans of an adhesi-ve'strip 36} with-shoulders disposed inwardly from said fiatin such a wayas to' form acontinuousstrip with tened portion; a" f'r'iction lining affixed to said the' abrasive surface 3t externally disposed-and top'and bottom' walls and :said smoothly roundedthe backing surface w internally disposed; end wall, a removable flexibly-backedabrasive While the dimensions of this strip -must con strip-incoritinuous form enveloping-the-top,lootform roughly to' those-'ofthe support block, it tom and-end wallsofisaid block,said-enveloped will' be apparent that by reason of i the variable top ahdbottomand said other of said'end walls longitudinal dimension L of that block, variable being exposed for abrasiveaction, the-side walls because of the contractible andexpansible v, ofsaid blocklbeing exposed 'to b'e grasped by the pusher-bar of'assembly C, these dimensionsare operators" hand; a" sharply curved pusher bar not-critical. provided with -a pair of supporting arms each- The tension exerted by theexpansible means-" adapted met withinoneof said holes'insaid on 'the-abrasive strip, will tendto inhibitislir'iping supporting block; and aicoil spring loosely surbetween theblo'clrand the strip. However, in rounding each of 'sa-id supporting arms, each of order to reduce the slipping tendency to, amini- 3.35 said springs adapted' to have one end seated mum: it has been found desirable to attach-a-- against the shoulder in the appropriate holesfriction lining 33to. the block .on one-0r more of andthe other end-activeagainst'said pusher bar. those surfaces where the 'block' and the sand' saidpusherbar'being'looated between said'block paper'areincontact, which strip offers a highly andsa-id abrasive strip and resiliently urged' by frictional surfaceto the backing surface 40*i0f' said abrasive strip and resiliently'urged by said the; abrasive strip, thus preventing'the' abrasive: springs into contact withthe interior of said stripjfrom slipping. during use of the device; This": continuous abrasive strip so as to =be frictionally lining may be of, asbestos, felt, or'any, other suit active thereupon to releasably-holdthe-same unable frictional material. a I I The manner of use of this device should be block, thestripbeing rotationally movable over apparent from the above description; A strip off, the top, bottomand end'walls" of the block and" fonexample, sandpaper: of suitable. dimensionisj over said pusher-'bar fonbringing afresh abrasive cut'from any commercial source, the free'ends'" Sur ace thereof over any desired one of said are fastened together and the nowicontinuous: Walls onlywhen'said springs are contracted, the strip'fisthen fitted overthe support assembly so" top-andbottoni'walls of said abrader in c0nJunc asto: envelope. all but the side walls; The de tion with said abrasive-strip defining broad vice is then ready for operation and anyjofithe" abrasivesurfaces', the bl'untlycurved end wall of support" surfaces can. be. used for. sending. orsaidblockin conjunctionwitli' said abrasive strip abrading. When the sa'ndpaper'surface. being; defining a bluntlycurved abrasive surface, and sed, h b worn t a point ofnonleff-ectiyez said pusher bar in "conjunction-with said abrasive mess; the expansible member maybe depressed, strip defining a curv'edfabrasive surface of exand 'thesandpaper rotated with respect to the tT'emEIIaTI'OWIIQSS- support'assembly until a fresh sandpapersur ATTO HANNA? face is presentedto the work. In the" em'bodi ment illustrated, if one fiat'surface becomes worn} 0 REFERENCES CITED der tensionin-non slipping'relationship to said" t de ce y merely b turned upside The following references are of record in the thus providing'for effective use another unwornji fil'epf this-patent: long-surface, and the device still presents fea tures of'convenience and non-slippagebetween PATENTS the sandpaper and the block. If'sandin'g is ne'c Number Name D'ate' essary on narrow surfaces or depressed areas, the 1,067,280 Smilovetz July 15, 1913 rounded ends of the block may-housed, and as" 1,921,211 Hawden' Aug. 8, 1933' the sandpaper becomes worn, a slight rotation 2,189,307 Bierma- Feb. 6, i940 of'the sandpaper withrespect to the: block will $270,835 Hibert Jan. 20, 1942 provide an unworn abrasive surface readyjfor 2,275,766 Johnson Mar. 10', 1942 use; In the embodiment shown, the convex 2,400,928 Hein May 28, 1946' pusher-bar provides anextremely'narrow sup= 

